Despite recent growth in formal work on allocutive marking, little work to date has considered the nature of cross-linguistic differences in the syntax of allocutive varieties, and what relationships, if any, exist among them. This paper summarizes recent formal results describing four kinds of variation across allocutive languages: (i) variable root-sensitivity; (ii) variation in allocutive morpheme placement; (iii) differences in allocutive morpheme type; and (iv) variation in interactions with clause typing and complementizers. We propose that the sole formal property unifying allocutive varieties is exponence of addressee features licensed by a silent Addressee DP. We further propose that variation in the properties of allocutive morphemes considered here reflect four principal loci of variation: (i) the position in which the silent Addressee DP may participate in allocutivity; (ii) the variable presence of a projection introducing an allocutive pronoun; (iii) the variable non-silence of a bound allocutive pronoun and/or the head introducing the Addressee DP; and (iv) agreement with other C-field heads. The analysis suggests that allocutivity involves greater formal heterogeneity than has been described previously in the literature. Principal aspects of cross-linguistic variation nevertheless can be modeled in terms of a limited set of formal options elsewhere motivated.